Three-dimensional pantograph machine tool



y 1944- H. KLEMA I THREE DIMENSIONAL PANTOGRAPH MACHINE TOOLS Filed March 22, 1943 2 Sheets-Sheet 1 Al Al May 9, 1944. KLEMA 1 2,348,632

THREE DIMENSIONAL PANTOGRAPH MACHINE TOOLS Filed March 22, .1943 2 Sheets-Sheet 2 Patented May 9, 1944 THREE -DIMENSIONAL PAN TO GRAPH MACHINE TOOL Harlow Klema, Racine, Wis, assignor to George Gorton Machine 00., Racine, Wis, a corporation of Wisconsin Application March 22, 1943, Serial No. 480,092

2 Claims. (Cl. 9il13.1)

This invention particularly relates to three-dimensional pantograph machine tools; and the objects and nature of the invention are brought out by the following description of the example of a preferred mechanical expression or embodiment of the invention illustrated by the accompanying drawings, from among other constructions and modifications within the spirit and scope thereof.

A certain type of three-dimensional pantograph engraving and other machine tools, provides a pantograph mounted to swing laterally on a vertical axial line, usually alined with the main supporting pantograph axis, toward and from which the pantograph is collapsible and expansible while maintaining the desired scaled relationship between the tracer or stylus and the cutter spindle, in conducting two dimensional operations. Where depth or third dimensional operations are desired, the cutter spindle and the tracer are vertically movable with respect to the pantograph along straight lines parallel with said axial line on which the pantograph is bodily laterally swingable; and a vertically and laterally swingable depth dimensional overarm, lever, or other suitable member is provided to translate vertical movements of the tracer into scaled vertical movements of the cutter, at the same scaled relation or ratio, as is maintained by the pantograph between the tracer and cutter during. lateral dimensional operations. This depth dimensional scaling lever is mounted to the machine frame to swing laterally with the pantograph on said vertical axial line of the pantograph pivot, and to swing vertically with respect to the pantograph axis on a transverse axis that substantially intersects and is substantially perpendicular to said vertical axial line.

This scaling lever usually extends transversely with respect to the cutter spindle and the tracer, and usually the lever is rocked vertically by the vertical movements of the tracer, and thus in sealed relation controls the vertical movements of the cutter spindle. In a preferred organization, said lever is joined to the tracer by a transverse pivotal or equivalent coupling to require longitudinal movement of the lever as the tracer laterally follows the copy or master pattern. In this arrangement the lever moves transversely across the vertical axial line of the cutter spindle and also transversely across said vertical axial line on which both the lever and the pantograph are laterally swingable as a unit. This arrangement usually requires a peculiar coupling between the lever and frame to confine the lever to swing vertically on said transverse axis hereinbefore defined, and to permit said free longitudinal movement of the lever through said coupling while maintaining the same against lateral displacement.

It has also been proposed to employ a depth dimensional scaling lever that is not longitudinally movable with respect to the machine frame, but is swingable vertically on a transverse axis at a point fixed with respect to the lever length. In this proposal both the tracer and the cutter spindles are coupled to the lever to rise and fall therewith and for relative sliding movements longitudinally of the lever.

Such machines as just described, are often required to remove a substantial area of the surface of the work to a required depth or depths, by laterally swinging the pantographwith the depth scaling lever to carry the cutte'r'back and forth across the full length or width of such work area or surface to gradually remove the material thereof by a series of concentric cuts of gradually re-' ducing or increasing radii, each out being approximately of the same radial width as the cross dimensions of the working portion of the cutter. It is difiicult, however, to accurately by hand steadily maintain the accuracy of such successive cuts and to accurately make the required radial feeding movement at the ends of arcuate cuts and to accurately and uniformly maintain the cutter at the exact required radial distance from said vertical axial line of the pantograph axis, throughout the full length of a cut. i

In the operation of such machines, the hand of the operator, applied to the tracer or other ap propriate part, must be relied on, to accurately move the tracer, cutter, and depthscaling lever radially toward or from said vertical axial line, to feed the cutter always the exact required distance at the termination of each arcuate cut, and to maintain such exact radial distance throughout the cut. The lever, tracer and cutter are necessarily freely and easily movable radially, and hence the hand must not only propel the parts on the swinging movements against the resistance of the working cutter, but must at the same time steadily maintain such parts against such radial movements.

It is an object of this invention to provide the depth scaling lever with simple, easily operated and set means for effectively correcting the above noted difiiculty, and for increasing the usefulness and efficiency of such machine tools by giving the operator firmer and steadier hand control over the cutter with resulting greater accuracy and heavier cutting possibilities as well as smoother finishing cutting.

With the foregoing and other objects in view, as developed by the following specification, my invention consists in certain novel structural features, and in combinations and arrangements, as hereinafter more fully explained, and as specified by the appended claims.

Referring to the accompanying drawings, forming a part hereof:

Fig. 1 is a side elevation, more or less diagrammatical, illustrating in part a three-dimensionah pantograph machine tool that includes a. longitudinally-movable and vertically and laterally swingable depth scaling lever, with an example embodiment of my instant invention applied to such lever.

Fig. 2 is a cross section on v the line 2-2, Fig. L.

Fig. 3 is a detail top plan of the portion. of the scaling lever, the embodiment of the instant inventionon said lever and the adjacent portion of the: coupling. between the lever and machine frame.

Fig. 4 is a detached view of said example embodiment.

The accompanying drawings disclose, in part, a. three-dimensional pantographl machine tool, of the sametype, general'construction: and operation as those.- disclosed: by U; S. Patents Nos. 2.1281311, and: 23613709 issued to George Gorton- Machine (20.01. Racine,.Wisconsin, as assignee, although I do. not wish, to; so. limit all features and adapta tions of my instant invention. Reference i'shereby made to the. aforesaidpatents for machine disclosures and explanations: not appearing herein.

In the machine disclosed by the drawings, any suitable-usuallyhorizontal pantograph l is. carriled by the. machine frame 2' and is: mounted thereto: to relatively swing laterally on. a main supporting: vertical axis. 3, carried: by saidframe.

This pantograplr carries a suitably mounted vertical? rotary cutter spindle 4 adapted at its depending lower end to carry and; drive a re placeable cutter 5. For depth scaling operation, this cutter spindle is. relatively vertically movableinthe pantograph and is usually spring pressed upwardly. Any suitable means is provided for driving said cutter spindle. The cutter spindle is usually held to. relative vertical movements in a. straight line parallel to the vertical axial line of the'pantograph axis 3.

The vertical tracer- 6 is also carrried by the pantograph. land: is vertically movable with respectthereto on. a. straight line: also usually parallel; with the axialli-ne of said pantograph axis. 3.

The pantographl, shown: as anexample from among. others, that might be employed, is of the parallelogram type wherein the fourarms are united onvertical pivotal linesfor contraction and expansion, and with said arms including a main supporting arm la, supported from the frame to swing laterally on pivot or' axis 3', and an elongated actuating: armlb, that carries the tracer 6-.

This pantograph is usually adjustable and settable to establish any suitable reproducin ratio between the tracer and cutter with respect to. they pantog-raph axis 3, particularly where the vertical axes of the tracer and the cutter spindle are inv the same vertical plane with the pantograph axis 3'.

As the pantograph. swings laterally on its axis 3, and is collapsed and expanded radially toward and from axis 3, the ratio relation between the tracer, cutter spindle, and axis 3, for which the pantograph has been adjusted and set, is constantly maintained.

The machine provides any suitable work holder 1, for the normally fixed work w, under and in operative relation to the movable cutter 5; and also any suitable holder 8, for the normally fixed master or copy pattern 9, under and in operative relation to the movable tracer 6.

To render the just described machine capable of thirdor depth dimensional work, it is provided with a depth divisional scaling member l0, preferably in the form of a longitudinally elongated: bar forming lever or over arm at its free end joined to. the upper end of the tracer 6, by a transverse pivotal connection ll, through the medium of which the lever is longitudinally moved endwise by lateral movements of the tracer in directions substantially radially of the axial line of the pantograph axis, and straightline, vertical: movements of the tracer correspondingly raise and lower the free end of the lever and rock the lever vertically.

An intermediate portion of this usually straight lever l0 traverses the longitudinal axis of the vertically movable cutter spindle 5, which is preferably spring-pressed upwardly against said lever.

The cutter spindle mounting usually provides a head 5a movable vertically with said cutter spindle with said head 5a, held pressed upwardly against and in sliding engagement with said spindle. Said head usually upwardly straddles said lever to prevent lateral deflection of the lever from said head, as the lever moves longitudinally in either direction transversely of" said head.

The lever I0, is mounted to the machine frame for relatively longitudinal movements, and for vertical and lateral swinging movements with respect to the frame. The. lever [0, in this example, is, vertically swingable on a fixed transverse axisv [3, that substantially intersects and is substantially perpendicular to the vertical, axial line of. said main supporting. axis 3 of the pantograph.

The coupling that confines the lever to the frame for such vertical and lateral swinging movements, can, for example, comprise a verti'cal yoke I4, confined to the frame to swing horizontally ona vertical axis alined with said vertical axis 3 of the. pantograph, and a vertically swingable frame, yoke, or guideway l5, arranged in, and carried by yoke l4, andv pivotally mounted thereto by said transverse axis l3, to swing as hereinbefore described.

The lever IQ is freely longitudinally movable through said vertically swingable confining: and guiding yoke i5, which through the medium of vertical opposite side walls 1-511, and its upper and; lower idler rollers 55b, engaging thetop and bottom longitudinal edges of the lever, confine said lever against objectionable lateral move ments, and holds said yoke It to vertical swing with. the lever.

My solution of the problem resulting from my discovery of the hereinbefore described difii cuities encountered in the practical operation of cooperative association with a complementary abutment, all so arranged that the operator in swinging the lever and pantograph laterally to produce an arcuate cut across the work accurately concentric throughout its length with the said main vertical axis of the lever and pantograph, can constantly exert pressure longitudinally of said lever and radially of said axis to firmly hold said stop means in contact with said abutment, and thus provide a steady-rest to steady the hand of the operator while swinging the lever and pantograph laterally, to prevent departure of the cutter from the desired accurately concentric curve of the desired radius. When such accurate arcuate cut is completed, such stop and feed means is adjusted and set to produce the arcuate return cut across the work of a radius slightly shorter or silghtly longer than the radius of the preceding out according to the radial width of said preceding cut. These forward and return cuts and adjustments are repeated until the material of the work area has been completely removed. In the particular embodiment illustrated, as an example, my invention takes. the form of an accessory or attachment applicable to and removable from and shiftable longitudinally along the depth scaling lever, although I do not wish to so limit all features of my invention.

The instant example provides a holder normally fixed to or on the depth scaling lever and this holder is provided with stop means normally fixedly located with respect to said holder, and capable of relative movement or adjustment to and setting at any desired position (within its capacity) longitudinally with respect to said lever to increase or decrease the radial distance between said stop and said vertical axial line of the pantograph vertical axis; as determined by any suitable normally relatively fixed abutment against which said stop can be positively held by the hand pressure of the operator while making arcuate cuts.

In the particular example illustrated, without intending to so limit my invention, the yoke 15, through which lever Iii is longitudinally movable and which swings vertically with the lever, is utilized to constitute the abutment complementary to said stop carried by the lever, although my invention contemplates mere reversal of the parts with the longitudinal adjustable stop carried by the yoke and the complementary abutment normally fixed to the lever. Where the stop is formed by an elongated rotary self-locking headed feed and stop screw, for example, screw I6, its holder, whether on lever H3, or yoke i5, constitutes a non-rotary complementary nut for said screw. Thus, I show the holder in the form of a non-rotary block H, in this example, carried by and normally fixed to lever iii, and provided with a screw threaded hole extending longitudinally therethrough and complementary to the thread of said screw.

In this example, the rotary screw it is arranged longitudinally of lever Iii, and extends completely through its holder H, with its outer end provided with head [6a, by which the screw is rotated through the medium of the fingers or a suitable instrument, and its inner stop forming end ifib, located in operative relation to the adjacent edge wall portion ld, of the yoke l5, that constitutes, in this example, the abutment complementary to said stop I61).

This holder i7 is, preferably, slidably mounted on the lever H], for adjustment longitudinally of the lever and for setting or fixing thereto at the desired radial distance from said vertical axial .line of the pantograph. For instance, I show said holder l1, formed to transversely straddle the lever Hi, from the top, if so desired, so that the holder rests on and is slidable along the top longitudinal edge of the lever, with the vertical side walls of the holder depending at and slidably contacting the opposite vertical longitudinal faces of the lever. One of said depending side walls of the holder is provided with a tapped hole extending transversely therethrough, for a complementary exteriorly-headed rotary clamping screw #3, by which the holder can be locked to the lever, or released for sliding adjustment thereon. However, I do not wish to limit my invention to such screw type means, for locking said holder.

The particular example embodiment disclosed constitutes an accessory or attachment which can be removed from lever Ill, when not required, and can be easily and quickly applied thereto and maintained thereon in operative position when needed.

The holder I! can be variously formed or constructed to render the same applicable to and removable from and adjustable longitudinally of levers I0, of various cross sectional formations. In the instant illustrated example, the holder ll happens to be thus formed for application to and removable from the particular lever I0, shown, by a longitudinal slot Ila, open at its ends through the opposite vertical end faces of the holder and opening throughout its length through the longitudinal bottom face of the holder, to thus provide the holder with the longitudinal closed top downwardly open slideway to rest on and straddle the lever II].

My instant invention is applicable to the three-dimensional pantograph machine tool that employs a depth scaling vertically and laterally swinging lever or overarm pivoted to the frame against relative longitudinal movement, with the cutter spindle mounting and the tracer both traversed by the lever and both slidable longitudinally of the lever, and constantly maintained by the pantograph in the desired scaled relation to each other and the vertical axial line on wliich the lever and the pantograph swing laterally, as are the cutter spindle mounting and the tracer in the instant illustrated example.

Where the machine tool includes the cutter spindle mounting and the tracer both slidable longitudinally of the depth dimensional overarm or lever that is held against longitudinal movements with respect to the frame, the holder I! will be applied to the lever I, either between the tracer and said vertical axial line or between the cutter spindle mounting and said line, with the screw it, directed toward either said mounting or said tracer with the screw stop end i Eb in operative contacting relation to some fixed part of either said mounting or said tracer that constitutes the abutment complementary to said stop end lfib. The operator with his hand on either the tracer or the cutter spindle mounting, while swinging the pantograph and lever on said vertical axial line to make an arcuate cut, will also exert pressure on said mounting or said tracer and hence on the pantograph toward said vertical axial line to maintain direct hand steadying contact between said abutment-forming portion of said mounting or said tracer and the stop end lfib, of screw it, the same as hereinbefore described, and thus gain the advantageous. results hereinbefore. pointed out. The feeding and stop operations will be the same as explained in connection with the illustrated example.

By the employment of my invention in threedimensional pantograph machine tools that employ a depth controlling overarm or lever, better and more eflicient cutter control is attained, and more efficient heavier cutting as well as smoother finishing cutting can be attained.

In the example illustrated, the radius of the arcuate cut is predetermined by the radial adjustment and setting of the stop toward or from the vertical axial line of the pantograph axis, and this radius is constantly maintained during a cutting operation by the strong radial lateral pressure of the hand through the pantograph toward said axial line while said hand is swinging the pantograph laterally on said axial line, whereby said stop held to positive contact with its. separate complementary abutment provides a steadying rest for the swing propelling hand.

What I claim is:

1. In a three-dimensional pantograph machine, tool that includes a depth cont-rolling overarm or lever swingable laterally with the pantograph on the same vertical axial line and relatively swingable vertically on a transverse axial line, and wherein the vertically movable cutter spindle and tracer carried by the pantograph are operatively connected to said lever to control the vertical movements of the cutter spindle by the vertical movements of the tracer; means swingable vertically and laterally with said lever for predetermining the radius of the arcuate travel of the cutter spindle when said pantograph and lever are swung laterally on said vertical axial line under the lateral pressure of the hand of an operator in a direction radially toward said vertical axial line, said means providing a steady rest for the radially pressing hand swinging said pantograph and lever, said means comprising a member carried by said lever, and a complementary member, one of said members being adjustable radially toward and from said vertical axial line and settable to predetermine the radius of said arcuate travel of the cutter, and the other member providing a complementary abutment.

2. In a three-dimensional pantograph machine of the type having a pantograph and a relatively-vertically swingable depth controlling lever, swingable laterally together on a common vertical axial line, with the pantograph maintaining the desired ratio relation of the relative ly vertically movable cutter spindle and tracer; stop and steady-rest means to predetermine and maintain the radius of an arcuate cut made by swinging the pantograph and lever laterally by hand while forcefully applying pressure to the pantograph radially toward said axial line to maintain constant stopping contact between said means and an opposing abutment, said stop means comprising a holder mounted on said lever, and a stop member adjustable and settable with respect to said holder radially toward and from said axial line and said abutment.

HARLOW KLEMA. 

